CHATTANOOGA, Tenn.— A gunman unleashed a barrage of gunfire at two military facilities Thursday in Tennessee, killing at least four Marines, officials said. The suspect also was killed.

A U.S. official, speaking on condition of anonymity to discuss an ongoing investigation, told The Associated Press the death toll included the four U.S. Marines and the sole gunman believed responsible. Two others, a soldier and a police officer, were wounded, the official said.

A U.S. official said the gunman in the shootings in Tennessee has been identified as 24-year-old Muhammad Youssef Abdulazeez.

He was believed to have been born in Kuwait, and it was unclear whether he was a U.S. or Kuwaiti citizen. The official was speaking on condition of anonymity to discuss the ongoing, sensitive investigation. It was not immediately clear whether the gunman's first name was spelled Muhammad or Mohammad.

He is from Hixson, Tennessee, which is just a few miles across the river from Chattanooga.

Authorities and officials say the gunman killed four Marines and wounded a police officer and others in two attacks on military facilities. The gunman was also dead.

The bodies of the four Marines who were killed in the shooting in Tennessee are being released by local investigators and will be flown to Dover Air Force Base in Delaware as early as Friday morning.

They will then be returned to their families, said a U.S. official, speaking on condition of anonymity because this person was not authorized to speak to reporters by name.

Their names have not been released.

"Lives have been lost from some faithful people who have been serving our country, and I think I join all Tennesseans in being both sickened and saddened by this," Gov. Bill Haslam said.

Law enforcement have swarmed the house believed to belong to the gunman authorities say killed four Marines and wounded others in two attacks on military facilities.

An Associated Press reporter saw officers with weapons drawn at the house and two females were led away in handcuffs. It's not clear who these females are.

The law enforcement presence came shortly after a news conference in which officials described the attacks.

Map of the shooting locations:

The U.S. Navy said in a tweet that there was a shooting at a Navy recruiting building on Amnicola Highway in Chattanooga.

A facility 7 miles away on Old Lee Highway also was attacked. Brian Lepley, a spokesman with the U.S. Army Recruiting Command in Fort Knox, Kentucky, said his recruiters there were told by law enforcement that the shooter was in a car, stopped in front of the facility, shot at the building and drove off.

The Army recruiters at the facility told Lepley they were not hurt and had evacuated; Lepley said he had no information about recruiters for the other branches at the facility.

Sgt. 1st Class Robert Dodge, 36, is the center leader for U.S. Army recruiting at that facility. He said four Army personnel were in the office at the time. He said the Air Force, Navy, Marine Corps and National Guard all have their own offices right next to each other. Around 10:30 or 10:45 a.m., Dodge and the others heard a gunshot, "which kind of sparked our attention," he said.

"Shortly after that, just a few seconds, the shooter began shooting more rounds. We realized it was an actual shooting," he said. They then got on the ground and barricaded themselves in a safe place. Dodge estimated there were 30 to 50 shots fired.

He did not see the shooter or a vehicle.

Police officers enter the Armed Forces Career Center through a bullet-riddled door after a gunman opened fire on the building Thursday, July 16, 2015, in Chattanooga, Tenn. Authorities say there were multiple casualties including the gunman. (AP Photo/John Bazemore)
Police officers enter the Armed Forces Career Center through a bullet-riddled door after a gunman opened fire on the building Thursday, July 16, 2015, in Chattanooga, Tenn. Authorities say there were multiple casualties including the gunman. (AP Photo/John Bazemore)

The Army recruiting office was not damaged, but doors and glass were damaged at the neighboring Air Force, Navy and Marine offices.

President Barack Obama has been briefed by his national security team on the shooting involving two military sites in Tennessee. White House spokesman Eric Schultz said the president will continue getting updates from his staff as needed.

Vice President Joe Biden, speaking at a summit of liberal activists in Washington, says said the United States will get to the bottom of the shootings.

Biden says said the young Marines killed were part of what he's calling he called "probably the most incredible generation that this country has seen." He's pointeding out that more than 4 million Americans have signed up for military service since 9/11, even though they knew they'd almost certainly be put in harm's way.

Biden says said the families of those troops have already given a lot to the country.

Biden is askeding Americans to keep the families of the victims in their prayers.

The Navy Operational Support Center and Marine Corps Reserve Center Chattanooga sits between the highway and a pathway that runs through Tennessee RiverPark, a popular park at a bend in the Tennessee River northeast of downtown Chattanooga. It's in a light industrial area that includes a Coca-Cola bottling plant and Binswanger Glass.

The two entrances to the fenced facility have unmanned gates and concrete barriers that require approaching cars to slow down to drive around them.

Marilyn Hutcheson, who works at Binswanger Glass just across the street, said she heard a barrage of gunfire around 11 a.m.

"I couldn't even begin to tell you how many," she said. "It was rapid fire, like pow pow pow pow pow, so quickly. The next thing I knew, there were police cars coming from every direction."

She ran inside, where she remained locked down with other employees and a customer. The gunfire continued with occasional bursts she estimated for 20 minutes.

"We're apprehensive," Hutcheson said. "Not knowing what transpired, if it was a grievance or terroristic related, we just don't know."

Reserve Recruitment personnel stand outside a Navy recruiting building as the area is cordoned off with blue shell casing markers in the parking lot on Thursday, July 16, 2015 in Chattanooga, Tenn. At least two military facilities in Tennessee were attacked in shootings Thursday, including one at a Navy recruiting building, officials said. (Tim Barber/Chattanooga Times Free Press via AP) THE DAILY CITIZEN OUT; NOOGA.COM OUT; CLEVELAND DAILY BANNER OUT; LOCAL INTERNET OUT; MANDATORY CREDIT
Reserve Recruitment personnel stand outside a Navy recruiting building as the area is cordoned off with blue shell casing markers in the parking lot on Thursday, July 16, 2015 in Chattanooga, Tenn. At least two military facilities in Tennessee were attacked in shootings Thursday, including one at a Navy recruiting building, officials said. (Tim Barber/Chattanooga Times Free Press via AP) THE DAILY CITIZEN OUT; NOOGA.COM OUT; CLEVELAND DAILY BANNER OUT; LOCAL INTERNET OUT; MANDATORY CREDIT

They've seen dozens of emergency vehicles rush by: bomb teams, SWAT teams, and state, local and federal authorities.

The Armed Forces Career Center on Lee Highway sits in a short strip between a Cricket Wireless and an Italian restaurant with no apparent additional security.

Near the other shooting location on Lee Highway, Nicholas Donohue heard a blast of gunshots while working at Desktop Solutions. But he had music playing and wasn't quite sure what the noise had been. He turned off the music and seconds later, a second blast thundered. He took shelter in a back room.

"Even though it knew it was most likely gunfire I heard, you also don't want to believe it's happening in the moment," he said. "Since I didn't see anything, I couldn't be sure."

By the time he emerged, police were cordoning off the area.

Bridis reported from Washington. Associated Press writers Travis Loller and Kristin M. Hall in Nashville, and Rebecca Reynolds Yonker and Claire Galofaro in Louisville, Kentucky contributed to this report.